Nearly 17,000 AT&T wireline employees in California and Nevada have been working without a new contract since April.

AT&T wireline workers in California and Nevada represented by the Communications Workers of America (CWA) union are putting more pressure on the company to reignite negotiations.

Nearly 17,000 wireline employees in California and Nevada have been working without a new contract since April.

Meanwhile, a separate contract covering another 21,000 wireless workers will expire in February.

Blitz Week

Register for FierceTelecom Blitz Week - June 15-18

As the telecom industry moves forward in the age of new technology, FierceTelecom Blitz week addresses the questions of how platforms, providers, and more will modernize to keep up with these fast-paced changes and their current status of implementing these changes. Join us June 15-18 to dive deep into the world of telecom transformation.

CWA told Fortune that AT&T and the union have not been able to come to terms over key issues such as outsourcing of call center jobs overseas, salary, healthcare costs.

The union said that 95% of the wireline workers have voted to approve a strike if necessary.

AT&T has been able to avoid the long labor strikes that hit fellow telcos FairPoint and Verizon.

Between 2015 and 2016, AT&T has successfully negotiated 25 labor contracts covering a total of 102,000 workers. In December, AT&T completed an agreement on a new contract covering 2,000 DirecTV call center workers, for example.

It hasn’t been completely smooth sailing for AT&T and the unions, however. A group of 2,000 workers in AT&T's internet business rejected a contract. The telco and the CWA worked out and approved a new deal a few weeks later.

For its part, AT&T maintains that it has offered the wireline workers in California and Nevada annual wage and pension benefit increases and healthcare plans that matches what other employees in other regions have ratified in other contracts.

“Our objective is to reach a fair agreement that will allow us to continue to provide our employees with solid union-represented careers with great wages and benefits,” said Marty Richter, an AT&T spokesman, in an e-mail to FierceTelecom.